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Live Loads in Construction Stages

Question:

I am running a model that has around 10 different construction stages.  At each one of these stages I would like to apply all of my loads including my lane live load.  Is there a way to apply live load at each construction stage and not just to the final stage?
Answer:

Hello,

The stages are mainly defined to check time-varying effects and sequential construction.  Moving load analysis isn't considered in each stage since its effects of creep are not considered, neither it changes the structural configuration.  That being said, it is necessary to check the structure for any critical live load placement.  So, these loads are defined as static loads that are activated & deactivated in the construction stage of 0 days duration.

Regards,
Midas Technical Support

So to clarify are you saying that there is no way to analyze the different construction stages with the lane live loads?  How would I convert these loads into static loads?  I need to be able to analyze the structure including the live loading throughout all of the stages. 

Hello,

To be clear, moving load analysis can't be done in construction stages.  So, we have 2 options here.
Method 1:  Obtain the critical vehicle positions for complete structure, convert them to static positions using the moving load tracer feature and activate relevant load cases in the appropriate construction stage.  This is a bit approximate method since we are not considering a change in stiffness of structure over time.
Method 2:  Save each stage as a separate model (Using the Save Construction Stage As... option), perform moving load analysis in these models to obtain the static positions, apply these in the complete model and activate/deactivate in relevant construction stages.  This method is exact.

As for converting any vehicle position to a static load case, kindly refer to our knowledge base article below.
1) Convert the moving load into static load using the moving load tracer feature, for the required vehicle position (Position for maximum moment or shear, as the case might be).


2) Copy the content of the generated text file

3) Go to Tools>MCT Command Shell and paste the content in the dialogue box


4) Hit Run. This will create a new static load case.
5) Create new load groups for different vehicle positions and assign these loads to appropriate load groups.
6)  Activate/deactivate these load groups in the appropriate construction stages.
Hope this helps.  Kindly let us know if further assistance would be required.

Regards,
Midas Technical Support
Creation date: 12/10/2019 12:12 AM (nandeep)      Updated: 12/10/2019 10:44 AM (nandeep)
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